Consolidated U.S. Household Energy Impact
Here's a somewhat famous household energy consumption chart used by world-famous smart growthers such as Peter Calthorpe and Jonathan Rose:
By "consolidated energy consumption," this chart shows a household's (a group of people living in a house or apartment together) energy consumption for operating the home (running lights, computers, refrigerators, heating/cooling) and for transportation to/from work and activities. This chart doesn't encompass items such as: a) the energy impacts of buying local, b) airplane travel, c) sharing power tools in your neighborhood rather than buying separate tools, d) going vegetarian, etc. This a useful way to look at individual energy consumption and to understand the impact of some crucial choices that we make.
The "suburban average 240 MBTU per year household" has a 2,000 square foot home. In the U.S., current single family home building practices are such that many homes are much, much larger than this. Home size has expanded dramatically in the U.S. in the past 30 years. Larger suburban homes consume far more than 240 MBTU per year.
If you live in a single family home and have a long SOV (single occupancy vehicle) commute, then your energy consumption is much higher than that of someone living in a smaller home in a mixed-use urban setting where you walk or take transit to work/activities. Green building techniques applied to your home further reduce energy consumption.
The energy consumption calculations can be found in this spreadsheet: http://www.cities21.org/HomeEnergyUseJonathanRoseLLC.xls . These are well supported calculations (references are provided), but you should expect that these sorts of figures will vary by +/- 10 percent, depending on the researcher making the calculations. If you live in an area with mild climate, your energy consumption is lower. If you live where it's very cold or very hot, then your energy consumption is higher.
Hence, we conclude that suburban U.S. "human settlement patterns" (land use and the associated trip distribution created by the people living in that area) are very inefficient. If we further examine the rest of the developed world, we find that the U.S. continues to stand out. NY Times writer David Brooks (from his 2004 book, On Paradise Drive) finds that the average home square footage per American is 770 square feet. Australia comes in second at 550 square feet, but the rest of the developed world requires far less square footage. Japanese take the least space, 136 square feet. In terms of climate impact, U.S. suburbanites represent one of the most serious threats to our climate. Countries such as China are beginning to develop U.S. style suburban enclaves - this inefficient suburban model appears to be something that other countries aspire to.
Are American Suburbanites Villains?
No. It's hard to fault people who followed the American Dream, worked very hard, saved up money, and bought a home in suburbia. There was almost no understanding of the negative environmental impacts of such suburban households as sprawling suburbia evolved in the U.S. Suburbia first evolved as a way to avoid some of the problems of big cities. But, now, with the spread of information about household energy consumption, Americans may be able to make more informed choices about the long-term consequences of the decision to follow the Suburban Dream. Buying a condo (or renting an apartment) and having a shorter, greener commute are two of the largest individual methods to cut energy consumption. Many other green actions produce much smaller reductions in comparison. Sure folks should buy fluorescent bulbs, but that's not the crucial item. Suburbanities who bought 4,000 square foot mcmansions shouldn't be pelted with vegetables so much as they should begin to consider whether there's a way they can offset their annual energy consumption in comparison to green urban consumption or Japanese consumption.